danm

hi i just had my 502 rebuilt, spun two main bearings, my oil temp will stay at 260 3000rpm wot 300 and wants to climb, i shut her down right away, i have a remote oil adapter which im not sure is plumbed right, it was like this when i got the boat. i spent alot to fix the motor and afraid its going to happen again, cant figure it out.




















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HARRISONMIRAGE

How big is your cooler.I just installed a 3"x18" combo cooler due to high oil temps in a new 502 motor.It would consistently climb when on the gas.With the new cooler I hit about 235 in the pan when I am on it.The down side is it takes a while to come up to temp.You might of fried your oil running it that hot.Is it posssible you had some tight bearing issues when you assembled it.Have you done mods that are creating more power than the original cooler was designed for.In my case the cooler was from a stock 330 horse motor and was not capable of the few hundred more ponies.

MACDAD260

Welcome to the board!

Is your motor stock or is it a custom setup? By that I mean does it have the stock Merc remote oil filter and cooler or not. If it is not stock could you describe what you have in a little more detail such as age of engine, any modifications for more power, size of boat, what type of drive, etc. With a little more info I am sure the guys here can give you some good advice on how to correct your problem.

danm

ya im running about 600 hp, it had a 454 in it and all the accessorys are from the 454 i checked the oil, it didnt smell burnt, the motor was built lose this time, i dont know what size the cooler is off hand, doesnt sound good right.

danm

its got brodix intake,rect-port alum heads,gil exhaust,gil pan,full rollerized,almost 600 lift cam, j@e pistons,msd ign,bravo 1 xr drive,a bit more cant think of it all.

paradigm shift

Stock cooler was not designed for that much HP. You are probably OK just need more cooling. Buy a bigger cooler built for 600HP. Depending on water temperature you run in an thermostat on oil cooler is advised. Will get oil temp up and maintain it. If you got it that hot I would change the oil also.

novaII

do you have a strainer on the water coming in and also check the intake side of the cooler for weeds and also impeller.oil temp will show before water temp so make sure you have good water flow first

MACDAD260

You need a much bigger cooler than the stocker. You should also upgrade the lines to 10AN (or 5/8") to get the flow you need so the oil does not bypass through the filter pad. You should change the bypass in the pad to a 30 psi unit. They are readily available at most GM dealers. The part # is 25161284. About 4 bucks. Avoid 90# fittings in the plumbing of the cooler if possible. Be prepared to spend about $500 (give or take a couple hundred) to get your oil temp under control or you will be rebuilding your engine again. This is the area that I see most often overlooked when adding horsepower to a stock setup. Do a search on oil coolers in this forum. There is a lot of valuable information from guys who have gone through this. Good luck.